Time Required

LAB 16

TEACHER’S PREPARATORY GUIDE /

Hot Spots

Cooperative Learning Activity
Group size: 3–5 students
Group goal: To use a model to study the development of an island chain over a geologic hot spot
Positive interdependence: Each group member should choose a role, such as map maker, whipped-cream sprayer, or observer.
Individual accountability: After the activity, each group member should be able to explain how an island chain forms over a hot spot and to identify the strengths and weaknesses in the model mentioned above.

Time Required

One 45-minute class period

Lab Ratings

TEACHER PREP

STUDENT SET-UP

CONCEPT LEVEL

CLEAN UP

Advance Preparation

Obtain copies (black-and-white or color) of a large map of the Hawaiian Islands that has a scale of at least 1:24,000. One such map is available from Map Link (ISBN 0-671-85050-4; phone: 1-805-692-6777; fax: 1-800-627-7768, online at Be sure to make enough copies so that there is one map for each student group. Each map should be about the size of a standard road map.

Provide enough cardboard for each student group to mount the map. To save time and materials, you may wish to mount, laminate, and punch holes in the maps in advance.

Be sure that the whipped-cream spray cans you use for this activity do not have to be upside down to work properly. After the activity, you may wish to provide the class with some foods that can be eaten with whipped cream, such as fruit or poundcake.

Shaving cream makes an excellent substitute for whipped cream.

Safety Information

Whipped cream cans that do not use nitrous oxide are now widely available. Instruct students to avoid pointing the can nozzles at one another and to be mindful of how much whipped cream they spray. Students should exercise caution when using scissors.

Teaching Strategies

You may wish to review the basic principles of volcano formation and plate tectonics with students before beginning this activity.

Evaluation Strategies

For help evaluating this lab, see the Teacher Evaluation of Cooperative Group Activity in the Assessment Checklists & Rubrics.

This checklist is also available in the One-Stop Planner CD-ROM.

Name______Date______Class______

LAB 16

STUDENT WORKSHEET /

Hot Spots

If you look at a map of the Hawaiian Islands, you might notice that the five main islands form a nearly straight line. That’s no coincidence. The islands are part of the Pacific plate, which is gradually drifting northwest over a hot spot. As the plate moves over the hot spot, magma from the hot spot erupts through the crust, creating underwater volcanoes that eventually become islands. These islands are carried away from the hot spot like packages on a conveyer belt, creating the island chain we see today. In this lab, you will simulate the formation of a chain of volcanic islands by a hot spot.

Ask a Question

How did the Hawaiian Islands form from volcanoes generated by a hot spot?

MATERIALS

map of the Hawaiian Islands
glue stick
piece of cardboard having the same dimensions as the map
scissors
metric ruler
spray can of whipped cream

Conduct an Experiment

1.Glue the map onto the cardboard. Allow the glue to dry.

2.Cut a hole about 1–2 cm in diameter in the map. The hole should be centered on the island of Hawaii.

3.Cut another hole in the map, this time on the island of Maui. Make sure this hole is at least 4 cm from the first hole.

4.Cut three more holes in the map on the three other main islands: Molokai, Oahu, and Kauai. Be sure that all the holes are spaced at least 4 cm apart.

5.Shake the can of whipped cream for a few seconds.

6.Move two small tables close together, leaving a gap of at least 5 cm between them.

7.Lay the map horizontally on the two tables so that the hole centered on the island of Hawaii is above the gap.

8.From under the map, have one group member spray a small amount of whipped cream through the hole while other group members watch from above. A small mound of whipped cream will slowly grow on the map surface. When the mound is about the circumference of a half-dollar, the group members who are watching should tell the other student to stop spraying.

9.Slowly slide the map horizontally so that the hole closest to the mound is above the gap between the tables.

Name______Date______Class______

Hot Spots, continued

10.Pass the spray can to another student in the group, and repeat steps 8–9 for the new hole.

11.Continue to repeat step 10. Be sure that every student in the group has a chance to build a whipped-cream mound.

12.After creating whipped-cream mounds over all five holes, pause to observe any changes occurring to the mounds. Then proceed to the discussion questions below.

Analyze the Results

13.What do the holes and the whipped cream represent?

14.How did the whipped cream mounds change over time?

15.What does this suggest about the relative ages of the five Hawaiian islands?

Critical Thinking

16.What physical processes might be at work to cause these changes?

Name______Date______Class______

Hot Spots, continued

Draw Conclusions

17.Which of the five Hawaiian Islands you examined most likely still have active volcanoes? Explain your answer.

18.Assume that the Hawaiian hot spot is still active. Is it possible for a new volcano to form another Hawaiian island? Explain your answer.

19.Identify two weaknesses of using whipped cream to represent the magma that formed the Hawaiian volcanoes.

Going Further
Not all volcanic islands are created by hot spots. Many, like the Aleutian Islands, form over convergent plate boundaries. Others, like Iceland’s island of Surtsey, form over divergent plate boundaries. Design an experiment to demonstrate how one of these other types of volcanic islands form.

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